“I bought a section in front of me here that now I can’t use. I wanted to get into market gardening and have some goats. But I have found the fluoride levels are five times higher than the recommended allowable level,” she said when approached.

Further up the hill, 1km from the works, Robert Morrison had hoped his retirement would involve a fair bit of gardening.

“Some of my silver beet had 120mg of fluoride,” he said.

“You would get shot, just about, if you sold silver beet with that much fluoride in it.”

Mr Morrison has stopped growing his own vegetables.

Nearby resident Rachel Gibb is a long-time campaigner over the fluoride from the works.

She fought for more stringent controls through the Environment Court for years and said yesterday the Otago Regional Council was still not doing enough to monitor the conditions set for the work’s discharges to air.

Since those conditions were set, pine trees had continued to die, house windows cloud over and leaves on other plants brown and curl.

Once the new scrubber was installed, vegetable testing needed to continue to ensure fluoride remained below10 parts per million and the regional council needed to take a lead, she said.

Mr Hendry said a change in the source of raw material used at Ravensbourne had resulted in increased fluoride emissions, damaging of trees and clouding of windows.

Damaged trees were being replaced and the company was seeking advice on the clouded window problem.